Injection wells are commonly used in oilfields to inject fluid back into an oil reservoir to force oil from producing wells. Typically, water that has been separated from the produced oil is pumped by surface pumps into the injection wells. The surface pumps may be of a variety of types.
One type of pump utilized downhole as a producing pump and at times on the surface as an injection pump is an electrical centrifugal pump. The pump assembly includes a pump made of a large number of impellers and diffusers. The pump is driven by an electrical motor. 1 It has been known to install an electrical pump assembly of this nature directly in line with an injection or main flowline from the water source to the injection well. The pump boosts the pressure of the fluid flowing through the injection line. On disadvantage is when the pump needs to be repaired or replaced, the flow through the main flowline to the injection well must be shut down while the pump is uncoupled from the main flowline and replaced or repaired.